Rayovac has been making batteries for over 100 years, and their batteries were commonly found in use with many types of battery-operated tube radios. Most commonly, radios would operate on 45V batteries with a tap half-way (for 0-22.5-45V). Two in series would give you 67.5V and 90V for bigger radios. This style has been out of production for many years, but Rayovac has a good modern replacement for the older Type 783 batteries, the 45V-HD.

It has connections for a modern connector as well as the old-style connections:

If you have a ’20s or ’30s battery radio, and want something more original than using a stack of 9V cells, this looks like a good bet!